High blood pressure is a major public health problem that affects nearly 25 percent of adults in the United States and contributes to increased risks of morbidity and mortality via cardiovascular and renal diseases. Although anti-hypertensive medications are often effective in the treatment of hypertension, non-pharmacological therapies are recognized as important first-line or adjunctive treatments for blood pressure management. A variety of relaxation and stress management techniques have been tested for their potential contributions to blood pressure control through stress reduction. Among these interventions, meditation training has shown the greatest promise as an adjunctive behavioral treatment for lowering blood pressure. This project investigates the effectiveness of a meditation-training program for the reduction of blood pressure. The 3-year study is a randomized, controlled clinical trial involving 120 adult men and women with hypertension or high-normal blood pressure recruited from the community. After extended screening and baseline testing, participants will be assigned at random to receive the experimental meditation training program (N= 60), to receive a progressive muscle relaxation training program that serves as a placebo control (N = 30), or to continue with usual care (N= 30). Post-treatment testing will be conducted 1, 2, and 3 months after training begins. Treatment outcome will be assessed by changes in laboratory-based and 24-hour ambulatory measures of blood pressure from baseline to follow-up. In addition, the study will test whether stress-reduction is a plausible mechanism that can account for clinical outcomes, using measurements of treatment-related changes in neuroendocrine and subjective measures of stress. Finally, the study will investigate the characteristics of those who respond best to this treatment and determine whether those individuals who begin training with higher levels of stress and anxiety show greater improvements in blood pressure and measures of stress than those who begin with lower levels. Meditation training may be a cost-effective non-pharmacological treatment for the management of high blood pressure. The results of this trial will advance our understanding of the potential benefits of this behavioral intervention, the mechanisms through which it works, and the kind of person who will benefit most from it.